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authorTom Zanussi <zanussi@kernel.org>2022-01-28 14:08:26 -0600
committerSteven Rostedt (Google) <rostedt@goodmis.org>2022-02-10 22:27:33 -0500
commitedfeed318d59ff242e895bf906223fc0b915117c (patch)
tree2464220317f5fd689ac50e78ab805b292002e318 /kernel/trace/trace_events_hist.c
parent1581a884b7ca5592270caa010a910f2ed4f7b5f5 (diff)
tracing: Remove size restriction on hist trigger cmd error logging
Currently, hist trigger command error strings are restricted to a length of MAX_FILTER_STR_VAL (256), which is too short for some commands already seen in the wild (with cmd strings longer than that showing up truncated in err_log). Remove the restriction so that no hist trigger command error string is ever truncated. Link: https://lkml.kernel.org/r/0f9d46407222eaf6632cd3b417bc50a11f401b71.1643399022.git.zanussi@kernel.org Signed-off-by: Tom Zanussi <zanussi@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/trace_events_hist.c')
-rw-r--r--kernel/trace/trace_events_hist.c30
1 files changed, 23 insertions, 7 deletions
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index ada87bfb5bb8..5e8970624bce 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -727,11 +727,16 @@ static struct track_data *track_data_alloc(unsigned int key_len,
return data;
}
-static char last_cmd[MAX_FILTER_STR_VAL];
+#define HIST_PREFIX "hist:"
+
+static char *last_cmd;
static char last_cmd_loc[MAX_FILTER_STR_VAL];
static int errpos(char *str)
{
+ if (!str || !last_cmd)
+ return 0;
+
return err_pos(last_cmd, str);
}
@@ -739,12 +744,19 @@ static void last_cmd_set(struct trace_event_file *file, char *str)
{
const char *system = NULL, *name = NULL;
struct trace_event_call *call;
+ int len = 0;
if (!str)
return;
- strcpy(last_cmd, "hist:");
- strncat(last_cmd, str, MAX_FILTER_STR_VAL - 1 - sizeof("hist:"));
+ len += sizeof(HIST_PREFIX) + strlen(str) + 1;
+ kfree(last_cmd);
+ last_cmd = kzalloc(len, GFP_KERNEL);
+ if (!last_cmd)
+ return;
+
+ strcpy(last_cmd, HIST_PREFIX);
+ strncat(last_cmd, str, len - sizeof(HIST_PREFIX));
if (file) {
call = file->event_call;
@@ -757,18 +769,22 @@ static void last_cmd_set(struct trace_event_file *file, char *str)
}
if (system)
- snprintf(last_cmd_loc, MAX_FILTER_STR_VAL, "hist:%s:%s", system, name);
+ snprintf(last_cmd_loc, MAX_FILTER_STR_VAL, HIST_PREFIX "%s:%s", system, name);
}
-static void hist_err(struct trace_array *tr, u8 err_type, u8 err_pos)
+static void hist_err(struct trace_array *tr, u8 err_type, u16 err_pos)
{
+ if (!last_cmd)
+ return;
+
tracing_log_err(tr, last_cmd_loc, last_cmd, err_text,
err_type, err_pos);
}
static void hist_err_clear(void)
{
- last_cmd[0] = '\0';
+ if (last_cmd)
+ last_cmd[0] = '\0';
last_cmd_loc[0] = '\0';
}
@@ -5610,7 +5626,7 @@ static int event_hist_trigger_print(struct seq_file *m,
bool have_var = false;
unsigned int i;
- seq_puts(m, "hist:");
+ seq_puts(m, HIST_PREFIX);
if (data->name)
seq_printf(m, "%s:", data->name);